收集48例牛奶过敏病人和27例阴性对照样本的血清，用酶联免疫法检测针对α-乳白蛋白（Bos d 4），β-乳球蛋白（Bos d 5），α-酪蛋白（Bos d 9）, β-酪蛋白（Bos d 11）, and κ-酪蛋白（Bos d 12）的特异性IgE。
在牛奶过敏的人群中，大多数人至少对一种牛奶蛋白敏感;大约一半的人对Bos d 5、Bos d9、Bos d11和Bos d12分别敏感，而对Bos d 4血清sIgE阳性的人很少。Bos d 12特异性IgE曲线下面积最大(AUC) (0.878;95% CI(0.800-0.957)，因此在鉴别牛奶过敏和非牛奶过敏患者方面表现出最好的诊断性能，使用统计学上最优的cut-off值 (OD450nm, 0.191)，灵敏度为92.6%，特异性为72.9%。Bos d 5 + Bos d 12的组合显示AUC的值为0.926,它比任何单组份的都高。
我们的研究结果揭示了不同牛奶过敏原成分致敏的个体间差异。在牛奶过敏诊断中，Bos d 12特异性IgE表现最佳。应用基于logistic回归的ROC曲线，进一步提高牛奶过敏原组份组合对牛奶过敏诊断的准确性。
Component resolved diagnostic study of cow's milk allergy in infants and young children in northern China
Increasing dairy consumption in China has been accompanied by rising incidence of milk allergy. Here we analyzed profiles of specific immunoglobulin E (sIgE) against cow's milk proteins, and assessed their value for milk allergy diagnosis among infants and young children from northern China.
Sera collected from 48 patients with milk allergy and 27 negative control subjects was analyzed by enzyme-linked immunosorbent assay to measure sIgE to α-lactalbumin (Bos d 4), β-lactoglobulin (Bos d 5), α-casein (Bos d 9), β-casein (Bos d 11), and κ-casein (Bos d 12).
Among milk-allergic individuals, most were sensitized to at least one milk protein; about half were sensitized to Bos d 5, Bos d 9, Bos d 11 and Bos d 12, respectively, while few had positive serum sIgE against Bos d 4. Bos d 12 sIgE had the largest area under curve (AUC) (0.878; 95% CI, 0.800–0.957) and thus showed the best diagnostic performance in discriminating between milk-allergic and non-milk allergic patients, with a sensitivity of 92.6% and specificity of 72.9% using a statistically optimal cut-off value (OD450nm, 0.191). The combinations of Bos d 5 + Bos d 12 showed an AUC of 0.926, which was larger than for any individual components.
Our results revealed inter-individual variation in the sensitization to different milk allergen component. Bos d 12 sIgE showed best performance in diagnosing milk allergy. Milk allergy diagnostic accuracy was further improved using combinations of milk allergen components by application of ROC curves based on logistic regression.